Project Summary. Chronic pain is a highly prevalent and disabling condition that is associated with heightened risk for opioid use disorder and overdose.1-4 Given the current opioid epidemic,5 it is essential to identify factors that could be associated with heightened opioid misuse in patients with chronic pain and could be potential novel treatment targets to reduce the risk of misuse and overdose in this at-risk population. Of note, chronic pain conditions are characterized by affective variability, resulting in frequent, sudden shifts from positive to negative affective states, often as the result of pain worsening.14,15 While previous research has examined the association between negative affective states and opioid outcomes,16, 17 affective variability has been overlooked. This is a crucial gap in the literature, given that reactivity to emotional shifts may lead to the prolonged negative affective states that put patients at risk for worse opioid outcomes. To fill this gap, the present proposal will be a novel examination of the emotional processing construct contrast avoidance (CA) in patients with chronic pain. CA is defined as 1) discomfort with shifts from positive to negative emotion (i.e., contrasts) and 2) engagement in strategies to reduce or avoid contrasts (e.g., avoiding engagement with positive emotion).9 Research on CA has shown that contrasts are aversive and disabling in anxious individuals, leading to greater emotional reactivity toward unpleasant events that follow a contrasting state (e.g., relaxation).10,11 Similarly, pain experienced following a contrasting ? i.e., pleasant ? state, could be experienced as more aversive and salient than pain following a neutral state. Heightened reactivity to post-contrast pain could lead to greater opioid craving and misuse to cope with the contrast, rather than for analgesia alone. Opioid misuse could also reflect a desire to create a stable emotional state and preemptively avoid contrasts. That is, individuals with chronic pain who engage in contrast-reducing strategies (e.g., blunting their engagement with pleasant states) under threat of pain may be those who are more likely to use opioids to artificially stabilize their affect. The present study will be the first to test the association between CA and opioid misuse in patients with chronic pain. Specifically, this study will: a) Investigate the association between self- reported CA and opioid misuse in chronic pain patients receiving prescription opioids b) Determine whether greater reactivity to pain following a contrasting (i.e., pleasant state) is higher in opioid misusers than non- misusers c) Determine whether opioid misusers are more likely to engage in a contrast-reducing strategy, mainly blunting of engagement with pleasant stimuli under threat of pain. In examining CA, we will utilize neurophysiological measures that allow for the indexing of emotional reactivity and attentional salience that cannot be captured by self-report alone. This fellowship will provide invaluable training in psychophysiological methodology and chronic pain research that will prepare the applicant for a career as an independent clinical scientist examining the association between chronic pain and substance use disorders.